<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .container,
        .container2 {
            width: 600px;
            font-size: 20px;
            height: 200px;
            background-color: yellow;
            display: flex;



        }

        .container div {

            width: 100px;
            height: 100px;
            border: 5px solid black;
            background-color: red;
            flex: 1;


        }

        .container div:nth-child(1) {

            width: 100px;
            height: 100px;
            border: 5px solid black;
            background-color: cyan;
            flex: 1;


        }




        .container2 div {


            height: 100px;
            background-color: red;
            flex: 1 0 0;
            border: 1px solid black;

        }

        .container2 div:nth-child(1) {

            width: 200px;
            height: 100px;
            background-color: cyan;
            flex: 1 0 auto;


        }
    </style>
</head>

<body>
    <div class="container">
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
    </div>
    <div class="container2">
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
        <div class=""></div>
    </div>




</body>

</html>